Ecological aspects of meadow phytocenoses

The article states that meadow phytocenoses are distinguished from others (forest, steppe, desert, water and others) by the dependence of composition structure (structure) communities on environmental conditions. At same time, onions differ agrophytocenoses arable lands. On land, in process crop rotation every year (or with a break one chain peren-nial grasses), existence phytocenosis is disturbed agricultural machinery used to cultivate soil. Therefore, crops grain or row always available for spread weeds. In order control their number, it necessary use an integrated system plant protection, which includes agrotechnical measures, biological chemical methods control. meadow, unlike such agrophytocenosis, closed weeds, since there competitive relationships between populations part it. It substantiated as result competition differentiation niches, formed – height difference aerial parts depth root systems. There no clear layers above ground below grass stands, but sometimes stable combinations species repeated like spots. Such spots called micro groups, phenomenon itself mosaicism. However, mosaicism not very common usually associated distribution leguminous components, have stronger impact environment than other species. Leguminous grasses known enrich soil nitrogen activity fixers symbiotically them, favorable years they form many leaves, can limit growth light-loving was noted peculiarity correspondence smallest changes conditions, forest will be leveled strong influence trees, land somewhat cultivation, application fertilizers sowing. rapid spatial variability only qualities these plastic communities. Meadow change over time quite quickly. worth distinguishing 2 types reversible irreversible. first case, seasonal changes, fluctuations weather conditions different years, intensity pasture use, outbreaks number certain grasses, nematodes pest insects grasses. second under anthropogenic factors (hay mowing fertilization) or, contrary, self-restore after cessation factor. should main variants successions observed phytocenoses: caused internal causes (autogenic) external (allogenic). meadows allogenous, related mode use. Most often, cause human Autogenous most often restorative nature.